it seems that libcurl 7.55 introduced an issue which causes NetworkManager connectivity check to fail 
There is an (already merged) upstream pull request which fixes the issue .
Kindly requesting a backport of the fix  to the affected releases Fedora 27 and rawhide.
Sure. This is easy to backport. Thanks for the notice!
fixed via https://src.fedoraproject.org/rpms/curl/c/b2dab7f3
(In reply to Kamil Dudka from comment #2)
> fixed via https://src.fedoraproject.org/rpms/curl/c/b2dab7f3
How about the F27 build?
(In reply to Bastien Nocera from comment #3)
> How about the F27 build?
*** Bug 1485609 has been marked as a duplicate of this bug. ***